Erin Burke, Section Chief of the Child Exploitation Investigations Unit at Homeland Security, poses for a portrait inside the Victim Identification Lab, part of Homeland Security's Child Exploitation Investigations Unit, in Fairfax, Va., Friday, Nov. 22, 2019. The Homeland Security Investigations section's little-known Child Exploitation Investigations lab is where agents scour disturbing photos and videos of child sexual abuse. They look for unlikely clues that help them...
Erin Burke, Section Chief of the Child Exploitation Investigations Unit at Homeland Security, poses for a portrait inside the Victim Identification Lab, part of Homeland Security's Child Exploitation Investigations Unit, in Fairfax, Va., Friday, Nov. 22, 2019. The Homeland Security Investigations section's little-known Child Exploitation Investigations lab is where agents scour disturbing photos and videos of child sexual abuse. They look for unlikely clues that help them... Credit: Jacquelyn Martin

FAIRFAX, Va. — It was the odd-looking locker handles that caught their eye.

Investigators spent hours poring over graphic images of little boys changing in and out of their swimsuits at what looked like a YMCA. They were hunting for any clue to help them identify the location — and ultimately, the victims and the person who exploited them.

Then they noticed that the locker handles had unusual plastic hooks. They scrubbed the photos to remove the images of children, then sent the pictures to locker manufacturers. One of them recognized the lockers and said they had been installed at YMCAs. Eventually, investigators matched the photos to a YMCA in Sandusky, Ohio. That led to the suspect, a former Boy Scout leader.

These weren’t FBI or local police, but investigators from the agency that’s the poster child for President Donald Trump’s polarizing immigration policies: U.S. Immigration and Customs Enforcement. ICE’s Homeland Security Investigations section, tasked with investigating crime, has a Child Exploitation Investigations lab where agents scour disturbing photos and videos of child sexual abuse.

They look for unlikely clues that help them identify the children and bring their abusers to justice. In one case, it was the loud, persistent chirping of a bird. Another time, it was unusual playground equipment.

“We are looking at the hidden details, the things people aren’t looking at,” said Special Agent Erin Burke, the section chief.

The work of Homeland Security Investigations agents has led to thousands of child exploitation-related arrests. But being part of ICE has taken a toll. Funding for HSI has fallen as a greater share of ICE’s budget is devoted to removing immigrants. And the association with ICE has created friction.

Some cities and police departments refuse to comply with ICE on immigration matters, like alerting them to criminal suspects wanted for crossing the border illegally. Sometimes that bleeds into the HSI investigators’ work, too. Just having the email end in “ice.dhs.gov” can cause problems.

“Ninety-nine percent of what we do here has no immigration nexus,” Burke said. “But people have a hard time understanding this.”

ICE’s involvement in child pornography investigations dates back to when hard-copy images were traded over borders. Now it’s all online. The internet has made it so investigators around the globe can’t keep pace with the tens of millions of graphic materials available today. It’s exploded in part thanks to cheaper online storage and easier encryption tools. The dark web gives additional cover to perpetrators. It has made them bolder, their abuse more graphic and disturbing, the work of the investigators more difficult.

The lab was created in 2011 to look for clues within images to help find child victims. It has three analysts and one special agent. They work in a small windowless room in a nondescript office building in the Virginia suburbs outside Washington. A sign on the door says in red bold letters: “Examination of graphic material in progress.”

Inside, new technology meets old: Fluorescent office lights are turned down and specialized blue lights glow. Giant, state-of-the-art computers with high-definition screens are set up alongside old police sketches of faces.

The cases come to them from local police, or international investigators who notice American victims. It can take two weeks, two days, two years to identify the children. Some they can’t find. Those children haunt them.